1. Field of the Invention
The present invention relates to a matting agent applying device and an inkjet recording device.
2. Description of the Related Art
Conventionally, inkjet printers have had the problem that printed matter, for which processing is completed, are damaged due to a phenomenon known as blocking in which inks on stacked printed matter adhere (bond) to one another due to insufficient drying and insufficient fixing of the image portions. In high-mass-production inkjet printers in particular, because there is the tendency for the drying and fixing time to be short, it is easy for insufficient drying and insufficient fixing to occur, and further, it is easy for blocking to arise when carrying out printing on thick paper.
Such blocking may arise, in addition to inkjet printers, in offset printers as well for example. In offset printers, blocking is prevented by spraying, onto the sheet surfaces, a powder for preventing adhesion between sheets.
However, with a powder spraying method, the problem arises that the printer interior is dirtied due to diffusion of excess powder, and, when carrying out double-sided printing, due to powder that has been supplied to printed matter dropping-off at the time of printing the reverse surface. In particular, in an inkjet printer of a type that carries out printing by coating a pre-processing liquid onto the sheets, the powder spraying method may become problematic with respect to the points that the powder may become mixed into the pre-processing liquid coating section, or poor ejection may be caused due to the powder adhering to the inkjet heads.
Thus, an image recording device has been disclosed that, in order to prevent blocking due to the ink of printed matter immediately after printing and before drying, transfers a powder, that is attracted to and held at the outer peripheral surface of a rotating roller, onto the ink on the printed image surface of the printed matter, by the viscosity of the ink (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 09-011654).
Or, there is a method (see, for example, Japanese Patent No. 4010577) in which a matting agent is affixed at predetermined intervals onto a sheet by an affixing roller having concave portions at the surface thereof, and diffusion of the matting agent within the printer is prevented, and the matting agent is prevented from dropping-off due to the matting agent being dispersed within a solvent that is adhesive. Further, there is a method in which a matting agent is prevented from dropping-off due to the matting agent being dispersed in a solvent that is not adhesive, and, after coating onto the printed matter, heating is carried out, and the solvent is thereby evaporated and the matting agent is fused and fixed.
In the structure disclosed in aforementioned JP-A No. 09-011654, the powder is supplied only to the printed image surface of the printed matter. Therefore, the powder does not overflow off of the printed matter after printing, and only the minimum needed amount of powder is used, and there is the effect of cutting-down on the amount of powder. However, because a powder is used, dirtying of the device interior cannot be avoided. Moreover, because the rotating roller wipes-off particles that have been transferred once onto the printed matter, there is the problem that the efficiency of transferring the powder is low and a sufficient performance cannot be obtained.
Further, the structure of Japanese Patent No. 4010577 discloses a method in which a matting agent is prevented from dropping-off by dispersing the matting agent in an aqueous solvent that has an adhesive function. However, although dirtying of the device is improved, it is easy for ink to gradually remain in the concave portions of the coating roller, and there is the problem that it is difficult to maintain good coatability (the ability to transfer the amount of the matting agent that must be applied). Further, when spraying powder particles, the amount of particles that is consumed itself becomes large.